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Aspects of leaching
1976 - IRG/WP 267
With respect to Document No: IRG/WP/246, and the recommendation that an economic leaching test can be based on a non-changing volume of water (500 ml/block), I would like to relate our experiences with this suggestion. Following 14 days of continuous immersion in de-ionized water it was found that blocks treated with moderate and above concentrations of a preservative gave no problems, but those blocks either having low chemical treatments or none (controls) produced a very healthy growth of slimy fungi and bacteria. Obviously these micro-organisms could be affecting the wood structure, should you wish to subsequently decay the blocks for biological toxicity evaluation. Also the micro-organisms could be degrading or otherwise modifying the preservative under evaluation. Under the old methods of "beaker leaching", with the water being changed daily, the growth of micro-organisms does not appear to be a problem. Any sugars leaching out into the water are removed within 24 hours and therefore the environment does not support their growth. The proposed method may be acceptable for leaching blocks containing a high retention of preservative (as reported in the paper), but as a method generally applicable to a concentration range of retentions, it does not seem to be acceptable. Obviously toxic agents could be added to the leaching water to prevent the growth of such micro-organisms, but this would have unpredictable effects on the wood-preservative-fungus complex under examination. I feel that this situation should be brought to the attention of the members of the IRG Working Group, since a non-biologist might not be aware of what has happened to his test and therefore present erroneous results.
R S Smith


An evaluation method for less termite attack execution on thermal insulation for fundation walls
2002 - IRG/WP 02-20245
According to the results by the real scale Japanese building tests, the termite installation was observed at very little spaces between foundation and insulation. The termite penetration spaces between foundation and insulation on foundation systems in Japanese wooden houses were checked by the way of streaming speed of colored water. Because of difficulty for its execution, the parts of outside angles and reentrant angles in continuous foundation were more sensitive for the termite penetration. Special accessories of thermal insulation for these angles can be effective for lesser termite installation.
K Suzuki, Y Tanaka


Pinus and Eucalyptus fenceposts treated with creosote and solvex tar by hot and cold open-tank process
1987 - IRG/WP 3455
A comparative study of the behaviour of two different wood preservatives, creosote and solvex-tar, was made, using two wood species, Pinus pinaster Ait and Eucalyptus globulus Labill, by the hot and cold open-tank process. Results showed that the creosote behaved better in relation with the uniformity of its distribution in wood. On the other hand, better results were obtained on Pinus for both preservatives.
M V Baonza Merino


Creosoted radiata pine by non-pressure methods
1988 - IRG/WP 3486
Posts of Pinus radiata have been impregnated with creosote by immersion for 1, 3, and 7 days, and by hot-and-cold open tank with hot bath temperatures at 40°C and 60°C. On the basis of the retention rates obtained, suitable procedures are described for wood elements that are going to be in ground contact, and an analysis is made of the way in which the variables tested affect the results.
M V Baonza Merino, C De Arana Moncada


The Rubber Ruler: Continuous measurement of dimension changes in wood panels
1994 - IRG/WP 94-20033
A new application for a linear transducer called Rubber Ruler was developed. Rubber Ruler provides a simple and reliable method for continuous monitoring of dimension changes in wood panels. This paper presents the methodology. Results of priliminary experiments designed to simulate the movement in wood panels are also discussed.
Siew K Ho, P Vinden, P Kho


Effect of sterilization method on germination of spores of wood decay fungi observed by contact agar block method
1978 - IRG/WP 2117
Previous studies of germination of spores of wood decay fungi on wood have generally concluded that method of wood sterilization has little significant effect on germination response. This study expands the numbers of test fungi as well as number of sterilization methods employed to determine the influence of sterilization method on spore germination response of decay fungi. Germination was assessed on agar discs fused by aqueous diffusion path to 1 cm³ samples of aspen and white spruce sapwood.
E L Schmidt, D W French


Experimental test site to prevent maritime pine logs from bluestaining: water-spraying and water-immersion methods
2003 - IRG/WP 03-10497
Following a storm which led to windfall wood, a research project was launched to develop preservation methods with a low environmental impact for maritime pine logs. These preservation methods are intended to be suitable for large-scale storage areas of maritime pine. In addition the aim was to maintain wood quality during long term storage. An experimental field test with 1 900 m3 of maritime pine logs was set up. In order to preserve the logs, water-spraying and water-immersion methods were tested. The impact of these methods on the development of bluestaining fungi and on mechanical properties was assessed. The first results after 8 months showed that whereas most of the untreated logs were bluestained, 73 % to 100 % of water-immersed logs and 94 % to 100 % of water-sprayed logs were preserved with less than 6 % of bluestained area. Moreover, neither preservation method led to a loss of modulus of elasticity or of rupture.
I Le Bayon, H Callot, D Reuling, C Brunet, P Castéra


The window joinery test hut
1975 - IRG/WP 257
D F Purslow


Leaching tests - A paper for discussion
1973 - IRG/WP 221
J W W Morgan


Creosote immersion treatments in fence-posts of Castanea sativa, Pinus nigra and Pinus halepensis
1988 - IRG/WP 3488
The method of soaking in creosote was applied to fenceposts of Castanea sativa, Pinus nigra and Pinus halepensis, taking into account its easy use in the field. Absorption, retention and penetration rates were recorded and analysed. Absorption rates were higher in Pinus nigra than in Pinus halepensis, and lowest in Castanea sativa. Thin fence-posts always absorbed more preservative than thick ones. Penetration rates were similar in both pines, and much higher than in Castanea sativa. Retention levels were almost the same in Pinus nigra and Castanea sativa, and lower in Pinus halepensis.
C De Arana Moncada


Protection of beech veneer for fruit and vegetable boxes
1981 - IRG/WP 3176
In Yugoslavia about 50,000 m³ of low quality beech logs annually are rotary cut into veneer from which boxes are made for transporting fruit and vegetables. Because of steaming before rotary cutting, beech veneer becomes extremely sensitive to mould attack which decreases the quality and commercial value of the final product. To avoid mould attack, veneer sheets are dried to 16% moisture content immediately after cutting. However, during transportation or cold storage of fruit, veneers or ready-made boxes can become rewetted and the mould problem can appear again. Some research work to determine suitable and non-tainting chemicals to prevent mould attack on veneers and boxes is described in this paper.
N Vidovic


A Long-term Observation of Termite Activity in The Nest by Continuous Acoustic Emission (AE) Monitoring
2003 - IRG/WP 03-20280
In order to evaluate the influence of temperature on the termite activity, acoustic emission (AE) monitoring was applied to two nests of Coptotermes formosanus SHIRAKI; a nest in the stem of a standing tree and a nest in the underground of a wooden house, respectively. Temperature change in and around the nests were continuously measured for about one year using thermocouples at four points; the centre of the nest, the periphery of the nest, the environment around the nest, and the underground, respectively. AEs were detected at the centre of nest and underneath the nest sphere by using wave-guides inserted into the nest of the standing tree and at the centre of nest. AEs were also detected at the wooden construction member near the nest in the wooden house. The termites in the nests were periodically stimulated by rotating, drawing and sticking the wave-guides. The temperatures in the both nests varied from 5 to 35 °C during the experiment. The highest and the lowest temperatures were recorded in August and February, respectively. The highest AEs event rate was recorded when the temperature of the nest in the tree was between 30 and 35 °C and when the temperature of the nest under the house was above 25 °C. In winter, when the nest temperature was below 10 °C, no significant numbers of AE were detected. These findings clearly show that AE generation has a close relation to the termite activities, which are influenced by the temperature in the nest.
Y Yanase, Y Fujii, S Okumura, T Yoshimura, Y Imamura


Wood preservation in Kenya
2000 - IRG/WP 00-40190
Focussing an Wood Preservation in Kenya, the Report discusses and elaborates on Education and Training, Research, Wood deteriorating organisms, Treatment Plants and Processes, Preserving Chemicals, Specifications, Markets, Health and Safety and Environmental issues. Education and Research is limited to one Institution only, other Institutions involved with the properties and utilization of wood hardly touches Preservation. Publications and results of Research Projects over the years have emanated from that Institution. Conferences have not been held for a long time in the country. Fungi, insects, including termites, and Marine borers, are all present in the country. The amount of untreated or poorly treated wood lost through the activities of these organisms is substantial. Treatment is usually of a general nature, assuming that Schedules used will protect timber against all agents of decay. The Kenyan Wood Preservation Industry, now 50 years old and with some 27 Plants around the country, has not explored other Wood Preserving Chemicals or Treatment methods. The four Preservatives used are still CCA, Creosote, BFCA and PCP. The Bethel Process is used by all pressure Plants (CCA and Creosote), with only one immersion Plant (BFCA and PCP). Eucalyptus, Acacia,Cypress and some are the species commonly treated, mainly for the local market with some exports. Schedules have not been properly worked out for different end uses. Transmission, Telegraph poles and Fencing posts comprise the bulk of timber treated, with smaller amounts of Construction timber and Horticultural poles. The four Chemicals used are of foreign origin, imported by Treatment Plants. Apart from a few Standards formulated by the Kenya Bureau of Standards (KBS), there are no other Standards or Codes of Practice to guide the Industry and Users of treated timbers. Specifications have not been fully worked out. The KBS is the only Authority responsible for Quality Control and Certification. Health and Safety of Plant operatives is not of major concern. Problems associated with Toxic Preserving Chemicals in the environment has not been fully addressed yet.
R Venkatasamy


Longterm monitoring of termite activity on multiple feeding sites: a laboratory method intended for the determination of attractant/repellent properties of wood preservatives and baits
2001 - IRG/WP 01-20225
A method is introduced allowing the continuous monitoring of the activity of a small laboratory termite- colony at 8 different feeding sites simultaneously. The test assembly consists of a small central polycarbonate-tube containing a colonie of Reticulitermes santonensis (de Feytaud) beeing connected with 8 external feeding sites by small glass-capillaries. The termites passing through the glass capillaries to and from the feeding sites are interrupting an infrared light-barrier. Each signal from the light-barriers is conditioned and fed to a PC-based signal-recognition-, monitoring- and storage-system. First results show that a colony of 500 individuals of Reticulitermes santonensis (de Feytaud) will need approx. 2 to 3 weeks for establishing a new, full functional hierarchy. A well established Reticulitermes- colony will show 80 to 100 passings per minute to and from the eight feeding sites. The activity of Reticulitermes santonensis (de Feytaud) shows no circadian activity rhythmic.
M Pallaske, E Graf, H Takiuchi


Report on the co-operative leaching tests
1975 - IRG/WP 246
The Work reported here was undertaken at the request of CEN to see (1) whether the standard beaker leaching method under discussion at CEN, and based on the German DIN could be made less labour intensive; and (2) whether the leaching parameters could be expressed in more general terms so that alternative procedures could be used. A co-operative experiment was set up in which the amount of leaching of copper and chromium from treated pine sapwood blocks was studied using modifications of the German DIN procedure whilst keeping certain operational parameters constant.
J W W Morgan


Preservative treatment of green timber by diffusion
1984 - IRG/WP 3291
The preservative treatment of green timber by diffusion is reviewed together with criteria which influence the economics of the process. New process options are described which should overcome some of the technical and economic disadvantages of double diffusion. These include the use of coagulating agents which increase the viscosity of the preservative solution and facilitate treatment by momentary immersion. It is anticipated that the main application for the diffusion treatment process will be for the treatment of refractory timbers for both ground contact and above ground exposure. The system is most suitable for low density and higher heartwood moisture content wood species - for example Sitka spruce, and is ideally suited for use in the tropics for treating both plantation grown softwoods and mixed tropical hardwoods.
P Vinden


Field fencepost test of several species treated with water-borne preservatives by rural methods
1986 - IRG/WP 3385
Fencepost field results in ground-contact treated by rural methods: immersion-diffusion and sap displacement by evaporation are analyzed. Copper-chrome-arsenic and copper-fluor-chrome preservatives were used in two concentrations. The wooden species studied were: Pinus pinaster, Eucalyptus globulus and Quercus rubra. For each of the test units decay index evolution was analyzed after five years exposure. At the moment, the best results are obtained with the immersion-diffusion method.
M V Baonza Merino


The lasting dehydration of wood treated by bifluorides worked up in Diffusec noticed by a continual drying of the wood
1999 - IRG/WP 99-30196
After an immersion of sound wood in a solution of Diffusec, in which a combination of acid potassium and ammonium bifluorides = FHF- in dissociated form is present, their potassium and ammonium fluoride ions together with the bifluoride ion = (FHF-) diffuse into the wood. They make use of the woodmoisture available as O-H-O bonds directly attached to the cellulose in the wood fibres to attract the dissociated ions, which after fusion are replaced by F-H-F bonds. If any substance that contains ions or centers of electric charge (from polar bonds) is brought into contact with water, sufficient electrical disturbance result in rupture of the hydrogen bonds. This means that the hydrogen bonds in water are readily broken. The released water dipoles are then attracted to these charge centers. Acid fluorides, as F- and FHF-, act permanently as F-H-F bonds upon OH groups of the cellulose. They are able to gather from the "watercoating" which surrounds the OH groups, so to speak thin layers which leave the wood in the form of vapour. Besides that they are able to occupy the vacant places. Near it watermolecules of the outer layers will easier release as those ones more directed inside. The uptake of the hydrogen in the air is dependent of the RH uptill air-dry wood is reached with the EMC belonging to it. No thermic intervention is necessary according to prof. dr. J. B. van Duijneveldt.
H F M Nijman


Preservative treatment of green timber by soaking in ammoniacal copper borate
1984 - IRG/WP 3292
Freshly sawn boards of radiata pine sapwood were preservative treated by soaking in ammoniacal copper borate. Optimum schedules were obtained by partially seasoning the boards for one week prior to treatment. This aided the absorption of preservative and reduced the required soaking time to approximately 2 hours. Complete boron penetration was obtained after one week of block storage under cover and air drying. Copper penetration was more limited because of fixation of copper. The preservative treatment system should have particular application in the treatment of coconut timber destined for above-ground use but exposed to the weather.
P Vinden, A J McQuire


Field fencepost tests of several species treated with water-borne preservatives by rural methods
1986 - IRG/WP 3385 E
Fencepost field results in ground-contact treated by rural methods: immersion-diffusion and sap displacement by evaporation are analyzed. Copper-chrome-arsenic and copper-fluor-chrome preservatives were used in two concentrations. The wooden species studied were: Pinus pinaster, Eucalyptus globulus and Quercus rubra. For each of the test units decay index evolution was analyzed after five years exposure. At the moment, the best results are obtained with the immersion-diffusion method.
M V Baonza Merino


Enhanced removal of CCA from treated wood by Bacillus licheniformis in continuous culture
1997 - IRG/WP 97-50083
A gram positive, spore-forming bacterium, which was isolated from a 20-year-old Forest Service test plot of CCA-treated 2 x 4's in Madison, WI., demonstrated the ability to release copper, chromium, and arsenic from CCA-treated wood in liquid culture. CCA-treated sawdust was exposed to this organism, which has been presumptively identified as Bacillus licheniformis. Analysis of the sawdust by atomic absorption spectroscopy revealed 80% reduction in copper and 43% reduction in arsenic when the sawdust was exposed to B. licheniformis in a standard mixed culture for 10 d compared to an untreated control. Enhanced release of metals was demonstrated when CCA-treated sawdust was exposed to the bacterium under continuous culture conditions in a chemostat. Steady-state growth of the bacterium under continuous culture conditions released 93% copper, 45% arsenic, and 6% chromium by weight from the sawdust. Exposure of CCA-treated wood to this isolate of B. licheniformis removed significant amounts of copper and arsenic from the wood.
C A Clausen


Creosote immersion treatments of fence-posts of different pines
1986 - IRG/WP 3386
This paper describes the preservation with creosote by immersion of fence-post of Pinus sylvestris, Pinus pinea and Pinus radiata. Taking into account the rural use of the fence-post, an easy method available in the field to the agriculturalists. A regressions analysis has been carried out, dealing with the absorption, retentions and penetrations shown after 1, 3 and 7 days of treatment. The greatest absorptions and retrentions were recorded in Pinus radiata, and the smallest in Pinus sylvestris. In the opposite, the penetrations have been quite different: maximal in Pinus sylvestris and minimal in Pinus pinea.
C De Arana Moncada


The Role of Moisture Content in Above-ground Leaching
2007 - IRG/WP 07-50245
This paper reviews previous reports on the moisture content of wood exposed above ground and compares those values to moisture contents obtained using simulated rainfall and immersion methods. Laboratory leaching trials with CCA-treated specimens were also conducted and the results compared to published values for leaching of CCA-treated specimens exposed above ground outdoors. Previous researchers have reported that the moisture content of wood exposed above ground may range from over 80% to minimums of approximately 10%. In most studies, the maximum moisture content fell within 40% to 55% for horizontal specimens and between 30% to 50% for vertical specimens. Minimum moisture contents were generally in the 10% to 15% range. Average moisture contents reported for horizontal exposures ranged from 21% to 26%, while the averages reported for vertical exposure were 19% and 25%. The simulated rainfall method produced a maximum moisture content of 49% in CCA-treated lumber specimens, but did not provide realistic drying between rainfall events. A 14-day continuous immersion with lumber specimens yielded an average final moisture content of 52% in CCA-treated specimens. Both methods produced cumulative copper and chromium leaching values slightly below, and arsenic values slightly above, those reported for wood exposed outdoors. Trials with smaller specimens indicated that immersion and drying schedules could be adapted to create moisture contents similar to those reported in service. Leaching methods could be improved by developing a better understanding of moisture conditions in wood exposed above ground, and of the role of drying cycles in preservative leaching.
S Lebow, P Lebow


Evaluating the Process of ACQ-Treated Woods with TGAand CEM Analysis
2007 - IRG/WP 07-20374
To provide an understanding of the fundamental thermal behaviour and the disposal-end products of ACQ-treated woods, this study is comprised of two categories of examination. The first is related to the use of TGA under different thermal decomposition conditions (nitrogen or air, and 5 or 40 oC/min), and the use of EDX to examine certain residual elements of the char. The second applies the CEM techniques to evaluate the emission gas concentrations of O2 and CO2 concentration, the emission content (CO, SO2, NOx), and the emission gases temperature were measured using a Flue-gas Analyzer from the exit of a 45° flammability testing cabinet as specified in the continuous emission monitoring. The results of the TGA showed that the char of ACQ-treated woods at air atmosphere were less than that at nitrogen, and the pyrolysis temperature for the heating rate of 5 oC/min was lower than that of 40 oC/min, but both them were with the same amount of char. The results of the EDX analysis of ACQ-treated woods obtained that the main element is C (77.89 %), and that the relative proportion of Cu was 2.67 %. The results of CEM indicated that the emission gas temperature of ACQ-treated woods rise rapidly up to about 250 oC and then slowed down in the temperature range of 200 oC shown as a Plateau curve. The concentration of O2 decreased from 20.7 % to about 17 % linearly, and on the contrary the concentration of CO2 increased from 0.2 % to about 2.5%. Both O2 and CO2 then approached the shape of a Plateau curve until the end of the combustion time, as well as had a close relationship during combustion. For the maximum value of the emission content during the combustion, the emission quantity of CO was about 160 ppm. The SO2 emitted gas was zero. The peak for NOx gas was 25 ppm.
Han Chien Lin, Tsang-Chyi Shiah, Jung Ting Tsai


Continuous moisture measurement (CMM) to detect failure of moisture resistance
2009 - IRG/WP 09-20422
A wood coating system will fail to perform properly after a certain time of weathering. From that moment, the substrate is especially prone to fungal attack. Moisture plays a key role on weathering performance, wood protection efficacy and decay susceptibility of wood. Therefore, knowledge of the moisture dynamics of the applied wood protection is of significant importance in the prediction of the service life of the wood coating system. Furthermore, weather action (abiotic) and biological factors (biotic) change the impact of moisture on the wood coating system. In this regard, this research focused on detailed monitoring of the moisture fluctuations of eight wood coating systems during outdoor weathering using a CMM (Continuous Moisture Measurement) set-up. Simultaneously, weather data were recorded. Data processing comprised correlation analysis, PCA (Principal Component Analysis) and cluster analysis on the functional moisture content data. In addition a laboratory evaluation combining artificial weathering with a floating test is discussed to determine moisture characteristics in a reliable way. Finally, these techniques are evaluated as a tool for the estimation of service life.
I De Windt, J Van den Bulcke, J Van Acker


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